This depends on what kind of nursing you want to do. Some nursing specialties require individuals to hold certifications before they can practice, such as nurse midwives. This is more common at the APRN level.
In other cases, certifications may be useful but not required. For example, you might pursue a gerontology, stroke, or continence care certification if you plan to work with older adults in long-term patient care facilities, but none of these are strictly necessary for all employers.